Such an engine balancer system is known from Japanese Patent Application Laid-open No. 2001-140985.
In this conventional balancer system, a balancer housing is formed by joining an upper housing and a lower housing, and oil within the balancer housing is discharged via oil discharge holes formed in mating faces of the two housings.
If an engine is mounted in a vehicle body with its cylinder axis inclined, since the mating faces of the upper housing and the lower housing of the balancer housing are also inclined, when oil within an oil pan is agitated there is a possibility that oil might penetrate into the interior of the balancer housing via an oil discharge hole formed in the mating faces on the lower side.